Method for thfe separation and rec



Aug. 22, 1944. 2,356,329

METHOD FOR THE SEPARATIONAND REGLAMATION oF COPPER FROM PRINTNG PLATESAND THE LIKE vFiled May 23, 1 942 Jr-el Zand) Patented Aug. 1944LAMATION F METHOD Fon 'ma PLATES Nnfrn Axel E. Lundbye, Springileld,Ohio, assignorto The Crowell-Collier Publishing Company,

SEPARATION AND REC- OPPER FROMIk PRINTING LIKE ` Springiield, Ohio, acorporation of Delaware Application May 2a, 1942-,- serial No. 444,228

' (cms-ss) 7 Claims.

My invention relates to Anew and.A useful improvements in a method forthe separation and reclamation of metals and .alloys that make upprinting plates and printing cylinders and other articles of e, likenature on which copper and i nickel may have been deposited.

The present application vdeals more particu metal iis especiallyvaluableand scarce-at this time.

The separation and reclamation of the Yand the backing metals from theplates will be mentioned, but the process for the recovery of the nickelforms the subject matter of my application Serial No. 447,582, led June18,1942.

- As is well known to those skilled in the art, the printing cylindersvor plates of the printing presses are composed of a base electrotypemetal consisting generally of an alloy of tin, lead and antimony, then asheet of tin foil for tinning purposes, after which there iselectrolytically de- -posited a layer of copper, over which thereisdeposited a layer of nickelfor the sake of hard- After these cylindersor printing plates have been used, they have generally been discarded orstored away, and although various means have beentried for theseparation and reclamation especially of the copper, still the processeshave been complicated, and the time taken to reclaim the nickel larlywith the recovery'of the copper, as this l copper covered a. relativelylong period, thus i making the recovery not practical from acommercialstandpoint.

One of the objects of the present invention. therefore, is to provide amethod for the recoving the copper from the backing material, and

'. alscthe recovery of the nickel, so that thisv copper can againbe'made into anodes and then redeposited on new printing plates and thebase metall and the nickel also recovered for refuse.

Another one of the objects of the present inery of the base metal andespecially for separate.

vention vis to provide a method for the separation and reclamation ofthe copper which will take but a relatively short time and thus keepdown the cost of the said reclamation process.

Still another object of the invention is to pro- 4vide a methodespecially for the recovery of the cospper inthe used printing pressplates, which method will effectively separate the copper from the othermetals or alloys making upthe ccmcover the copperfrom the printingplates which consists in removing thenlckel by an electrolytic process;removing the. base by heat; subjecting.

the copper shell also to heat; suddenly cooling; then a. knurling actionto .break up the scale; and a mechanical as lwell as a chemicalcleansing operation so that the copper can be quickly and readily againused for 'andes for the depositing. of -the copper on new printingplates and cylinders. l With 'these' and other objectsin view, theinventionv consists in certain new and novel steps for carrying outA themethod shortly to be oi1t. lined.

embodiment of my invention,

, `Fig. 1 is a small fragmentary section of a printing cylinder or plateafterit has been flattened and is ready to be treated, the tin foilbeing 'enlarged for the sake of clearness `of 'illusy tration; .f

lliig. 2 is similar to Fig. 1 but showing the nickel as having beenremoved; Fig. 3 is a view similar to Fig. copper shell remaining withits tin foil now the uppermost position; e

Fig'. 4- is a diagrammatic view of conveyor` rollers, pressure rollers,cleansing bath and means forheating the copper shell or plate on itstrip to the storage station; and

QFig. 5 is a fragmentary view showing how the 2 and shows the m.

reclaimed copper shell will appear when oo mpleted.

As heretofore mentioned, inthe method to be outlinedl'. not only recoverthe copper and the nickel, but also the base material; but the recoveryof these is incidental to the recovery of the copper and the recovery ofthe nickel forms the subject matter of my application Serial 447,582,nled June 18, 1942.

As heretofore mentioned, the printing plates as used in the large atpresses and cylindrical printing presses consist of a backing metal,which is an alloy of tin, lead4 and antimony, and designated by the wordBase inthe drawing.

In the several views I have shown the plate as being at, ratherthanarcuate, but, ofcourse, in

the recovery of the 'metal by my method, when the plates are ofcylindrical form, thecylinders are iiattene as may be seen in theseveral views.

A sheet of tin foil 2 is shown, which! have exaggerated' in thesev'eralviews ior'th'e sake of clearness, j' which tin foil is placed on therear face of the copper which acts as a tinning agent when the basemetal 3 is cast thereon. e

Referring to the drawing showing a preferred- It might be mentioned thatin the formation of printing plates there is a wax or lead mold madefrom an original copper etching and this lead or wax mold is then platedin a nickel elec- .troplatingtank with a nickel deposit of from .001

to .0015 of an inch. The mold with the nickel thereon is then subjectedto a copper plating where from .006 to .0012 of copper is plated on backofthe nickel. Then the mold with its covering of vnickel and copper isremoved from the tank and the lead mold stripped away. ',Ihe plate, nowof copper and nickel, is cut down to-size of the printing plate andplaced in a casting machine, copper side up, and at this stage the tinfoil is placed on the face of the copper-. Then the backing metal thatis the lead, tin and antimony is cast on the copper, the tin foil actingas a tinning medium.

It has been the general practice to store away these used plates orcylinders, and a number of processes have been devised for separatingand reclaiming the metals, but these methods have not come intopractical use due to the heretofore relative cheapness of the metals andtheir plentiplace before the plate is straightened out or afterwards.They are then cleaned with a hot, soapy Water. Y

After the ink has thus been removed, the plate is suspended fromtheanode bar of an electroplating tank (not shown). g

The proper solution and suilicient density of current is used to quicklystrip the metal from the outer or copper surface.

I have not shown the tank for the electrolytic stripping solution forthe nickel and it might be mentioned that the solution Will contain, inthe proper portions, muriatic acid and boric acid in aqueous solution.The boric acid acts as a' suitable buffer medium, and it is possible tostrip the nickel from the plate in from three to four minutes.

During the stripping action the plates should be supported by .theirrespective hangers, the

plates being secured by one corner, and after the Y It might bementioned here thatwliat little' copper has gone into the electrolytebath may be precipitated and recovered, but the presentinvention relatesto the main body of copper that has not been affected by theelectrolytic bath.

' After the printing plates have been treated as heretofore mentioned,they are now composed of 1 a base 4of an alloyof lead, tin andantimony.,

a thin film of tin and a layer of copper.

I next take the plates which are now in the form shown in Fig. 2 andcoat the upper or copper surface With' a thin coating of Whiting such ascalcium oxide or its equivalent. After the Whiting has been carefullyapplied, the plates are then placed in a melting pot (not shown) wherethe temperature is accurately controlled.

The temperature is held as close to the lower range of the melting pointof the base metals as possible, as it is not desired to add more heatthan is absolutely necessary to make the metal ow easily and it isdesirable to keep the oxidization of the antimony and tin to' the verymlntated so that the impurities will go to the top of the pot, while thebase metal is poured from the bottom of the pot.

A chemical analysis ofthe reclaimed base metal can be made at regularintervals to maintain the proper ratio of tin, lead and antimony. Ofcourse, the copper plates will be at the top of the molten metal.

The Whiting that was applied to the face of the copper prevents the basemetal from adhering to this surface during the melting of the basemetal.

The copper plate or shell appears as now shown in Fig. 3 (here againthetin foil being exaggerated for the sake of clearness of illustration)and I then place this copper shell on the conveyor rollers 6 as seen inFig. 4.

These copper shells or plates now have a thin coating of thebackingmetal that adheres very tightly due to the tinning operation in themaking up of the composite plate.

Of course, the tin foil has lost its original form, but it mixes with apart of the base metal and heretofore has been extremely hard to remove.However, by placing the plate on the roller 6 as heretofore mentioned,with the tinning on the upper surface, and by heating the copper shellsto a bright red heat, andy exposing the tinned surface-that is, theupper surface, to the air during the heating, I can oxidize theremaining tin land backing. metal and turn it into a hard, brittle scalein the course of from fifteen seconds to two minutes.

To provide the heat, there is shown a plurality of gasjets 1 positionedbetween the rollers 6 playirgtdirectly on the copper or underl surfaceof the p a e.

To further assist in loosening the oxidized scale from the copper shell,the shell is advanced beneath a. cold spray, as shown at 8, and thissudden cooling of the hot plate materially assists in also loosening andremoving the unwanted oxidized scale.

The plate then continues on its travel and passes between the rst twoknurling rollers 9, which tend to bend or corrugate the copper plate, asmay be seen in Fig. 5.

After passing through the rst two knurling rollers, the plate thenpassesI through the second pair of knurling or crimping rollers 9 whichare arranged to bend or undulate the metal in' an opposite direction. Inther` words, the small areas are first bent u ardly by the one set ofrollers, and then downwardly by the second, and

. this corrugating or bending action further pulverises and loosens thescale of oxidized metal,

Vthus leaving the ,copper relatively clean.

is removed from the plate'by the above-describedcleaning operations.

- Finally the plate moves under a spray jet where it is ag'ain washed toremove the muriatic acid and then drops to a, storage bin I3.

The plates are then dried and-may then be remelted and cast to be againused as anodes for depositing the copper on the base metal,-asheretofore mentioned.

It might be mentioned that one of the critical steps of the method isthe applying of the proper heat in a uniform manner to the copper plate,in order to thoroughly oxidize the film of backing metal. If this filmis not thoroughly oxidized, it will not separate from the copper duringthe crimping process of the roller. y However, with the properapplication of heat` to the copper, the lead, antimony and tin can beproperly oxidized in from fifteen seconds to two minutes. as heretoforementioned.

From the foregoing it will be seen that I have devised a method whereinall the. metals that make up the printing plates or other similararticles can be saved and reclaimed, the reclamation of the copperbeingthe important metal at this time.

It will be seen that the entire method from the scrubbing and flatteningof the plates until the time they have passed through the electrolyticbath, melting pot and apparatus mentioned,

consumes but a relatively short time, so that the method is not anexpensive one but, on the other hand, relatively fast and relativelyinexpensive. g It will be understood that the heating and coolingoperations, and the electrolytic action must be watched and regulated,but I have found the method in actual practice to give excellent resultsand quickly and readily separates the various metals from each other,and especially separates all of the tinning and base metal from thecopper plate, sothat the copper can be re meli:ed,v

cast and re-used as anodes with the same effect as if the copper werevirgin, rather than reclaimed. l V

It will also be seen that the apparatus may' be built at a. low cost andoccupies but a relatively small iioor space:

Finally, it will be understood that by utilizing a conveyor system forthe plates as diagrammatically illustrated, in which there is areceivingstation, a cooling station, a knurling station, a tank and adischarge station, the apparatus can be/ watched by a minimum number ofworkers or operators to thus keep down the'cost of the reclamation. Itwill, of course, be understood that rather than' having a storage bin asmen.-

tioned, a portable truck or other means might' be located under thedischarge station so that theA plates after being treated may be rapidlyremoved for recasting. I l

Having thus described` my invention, what I printing plates made up of abase metal with a coating of copper and nickel thereon, said base metalhaving a lower melting point than copper, which .consists inelectrolytically stripping off the nickel; coating the stripped surfacewith a Whiting; melting f off the base metal which leaves but .a thinI,coating of the same on one surface of the plate; oxidizing thethin.coating by heating and rapidly cooling the Yplate to change thecoating to a scale; distorting the surfaces of the plate in a pluralityof minute areas to thus crack and loosen the scale: and removing theloosened scale from said plate.

2. 'I'he vmethod of recovering the copper from printing plates made upof a base metal containing an al1oy-of lead, antimony and tin, and onwhich has been deposited a layer of copper and nickel, which co ists inelectrolytically stripping off the nickel; oating the stripped surfacewith a Whiting; subjecting the plate to a direct heat of suiilcienttemperature to melt the base metal and leave but a thin coating thereofon the-one surface of the plate; subjecting the non-coated surface toheat'from fifteen seconds to two minutes and rapidly cooling the plateby spraying .water thereon to thus oxidize the coating; subjecting theplates to rollers to bend the surfaces into a plurality of hills andvalleys and then to further rollers to change the hills into valleys andvice versa to thus thoroughly crack and loosen the oxidized scale fromthe copper surface, and mechanically and chemically remove the loosenedscale from said plate.

3. The method of separation and reclamation of copper from printingplates made up of a base metal comprising lead., tin and antimony, alaye of nickel, and a layer of copper between the baset metal and nickellayer, which comprises thoroughly cleansing the plate;'electrolytlca1ly'stripping the nickel from the surface of the copper layer; covering thestripped surface with whit ing and placing the plate in a melting potand melting olf the base metal for future recasting; heating the copperplate-by directing a hot flame against the stripped surface to oxidizeany film of base metal remainingbn the other surface of the copperplate, subjecting the plate to a cold spray to chill the plate and makebrittle the oxidized film; crimping the plate to loosen the oxidizedmetal lm; subjecting the plate to a cleansing brush and then to acleansing acid bath; and finally washing the plates with water to removethe acid.

- 4. The method of recovering copper from printing plates made up of abase metal with a coating of copper and nickel thereon. said base metalhaving a lower melting point than copper, which consists inelectrolytically stripping off the nickel; applying a protective coatingto the stripped surface, melting off the base metal which leaves but athin coating of the same on ing by heating and rapidly cooling the plateto change the coating to a scale; distorting the surfaces of the platein a plurality of minute areas to thus crack and loosen the scale, andreclaim as new and-desire to secure by Letters Patmoving the loosenedscale from said plate.

-5. The method of separation and reclamation of copper from printingplates made up of a base metal comprising lead, tin and antimony, alayer of nickel and a layer of copper between the base metal and nickellayer, which comprises thoroughly cleansing the plate, electrolyticallystripping the nickel from the surface of the copper layer, covering thestripped surface with vWhiting and placing the plate in a melting potand antimony which remains on the other surand melting olf the basemetal for future recastface ofthe copper plate, then quickly subjectinging. heating the copper plate by directing a hot the plate while stillhot to a cold water spray to name against the stripper surface tooxidize any quickly chill the plate and make brittle the relm of basemetal remaining on the other sur- 5 malnlng oxidized lm, crimping theplate to disface of thecopper plate, subjecting the plate to tort andundulate the surfaces of the plate to a cold spray to chill the plateand make brittle thus loosen the oxidized metal nlm on the ppper theoxidized film. crimping the plate to loosen lsurface of the'copperplate. brushing the plate to the oxidized film, and cleaning theoxidized metal remove the sealy film. cleaning the brushed plate iilmfrom the crimped plate. l0 with acid, and finally washing the plate tore- 6. The method of separating and reclaiming move the remains of theacid bath.

copper from printing plates made up of a base '7. vlin a 4method o'frecovering copper from a metal, comprising lead, tin and antlmony,tocopper plate having one relatively clean surface gether withsuccessive layers of tin, copper and and a coating of a metal on theother surface nickel superimposed on said base metal, which 15 thereofthat o xldizes at atemperature lower than consists in thoroughlycleansing the plate, electhe melting point of copper. oxidizingV saidcoattrolytically stripping the nickel of! the surface -ing by directinga flame against said clean surof the copper layer, covering the strippedsurface of said plate, distorting said plate in a pluface with achalk,lmelting oi the base metal, the rality of small areas to crack andloosen the oxchalk preventing the aforementioned metal from 20 idlzedcoating. and removing the loosened coattinning the stripped surface ofthe copper plate. ing. l heating the copper plate by directing a hotname AXEL E. LUNDBYE. on said stripped surface to oxidize the lead. tin

l thtthe same may co'no CERTIFICATE or CORRECTION. A Patent No.2,556,529. August 22, 19h14.

AXEL E. ALUNDBYE.,

Y It is hereby certified that error appee.rs in thev printedspeci'ficetion of the `above numbered patent requiring correction asfollews: Pego li, first coiumri, line li, claim 5, for the word that thes .d Letters Patent s'houd beraad with this correction therein rm to therecord of4 the case in thePatent Orifice. Signed and' sealed this 5rdday of Octber, A. D. 19h14..`

Leslie Frazer (Seal) Acting Ce'nnnissioner of PatehtsJ.

